Spring supporting structure for reciprocating compressor

ABSTRACT

A spring support structure for reciprocating compressor having a frame unit elastically supported inside a closed container; a reciprocating motor fixed at the frame unit; a compression unit having a piston combined to an armature of the reciprocating motor and a cylinder to be fixed at the frame unit; and a spring unit supporting a spring support provided at the armature or the piston and guiding a reciprocal movement of the piston. The spring unit includes a plurality of front springs supporting one side of the spring support in parallel and a plurality of the rear springs supporting the other side of the spring support. Because the front and rear springs elastically supporting both the armature and the piston are arranged in parallel to overlap with each other for a certain range, the horizontal length of the spring is reduced, resulting in a compact compressor.

This application is the national phase under 35 U.S.C. §371 of PCTInternational Application No. PCT/KR01/00868 which has an Internationalfiling date of May 24, 2001, which designated the United States ofAmerica.

TECHNICAL FIELD

The present invention relates to a spring support structure of areciprocating compressor, and more particularly, to a spring supportstructure of a reciprocating compressor for elastically supporting anarmature of a reciprocating motor.

Generally, a reciprocating compressor is to suck, compress and dischargea gas while a piston makes a reciprocal movement within a cylinder.

FIG. 1 is a vertical-sectional view of a reciprocating compressor of aconventional art.

As shown in FIG. 1, the conventional reciprocating compressor includes aclosed container 10 in which a suction pipe (SP) and a discharge pipe(DP) communicate to each other, a reciprocating motor 20 fixed insidethe closed container 10, a compression unit 30 installed in the closedcontainer 10 and sucking, compressing and discharging a gas, a frameunit 40 supporting the reciprocating motor 20 and the compression unit30, and a spring unit 50 elastically supporting the armature of thereciprocating motor 20 in a movement direction and inducing a resonance.

The reciprocating motor 20 includes a stator 21 consisting of an innerstator 21A and an outer stator 21B and an armature 22 inserted in anair-gap between the inner stator 21A and the outer stator 21B and makinga reciprocal movement along with a piston 31 (to be described).

The compression unit 30 includes the piston 31 making a reciprocalmovement by being combined to a magnet support member 22A of thereciprocating motor 20, a cylinder 32 fixed at a front frame 41 so thatthe piston 31 is slidably inserted thereto, and forming a compressivespace along with the piston 31, a suction valve 33 mounted at the frontend of the piston 31, opening and closing a gas hole 31 b of the piston31 to limit suction of a gas, and a discharge valve assembly 34 mountedat the front end face of the cylinder 32 to cover the compressive spaceand limit discharging of a compressed gas.

The frame unit 40 includes a front frame 41 supportedly contacting thefront side of the inner stator 21A and the outer stator 21B, with whichthe cylinder 32 is insertedly combined, a middle frame 42 supportedlycontacting the rear side of the outer stator 21B, and a rear frame 43combined with the middle frame 42 to support the rear side of a rearspring 52 (to be described).

The spring unit 50 includes a front spring 51, both ends of which aresupported at the front face of a combining portion of the armature 22and the piston 31 and its corresponding inner face of the front frame41, so as to be inserted into the outer circumference of the cylinder32, and a rear spring 52, both ends of which are supported at a rearface of the combining portion of the armature 22 and the piston 31 andits corresponding front face of the rear frame 43.

The operation of the conventional reciprocating compressor constructedas described above will now be explained.

When a power is applied to the outer stator 21B of the reciprocatingmotor 20 and a flux is formed between the inner stator 21A and the outerstator 21B, the armature 22 positioned at an air gap between the innerstator 21A and the outer stator 21B is moved in the flux direction tocontinuously make a reciprocal movement by virtue of the spring unit 50,and accordingly, the piston 31 combined with the armature 22 makes areciprocal movement within the cylinder 32, so that the volume of thecompressive space is changed and a coolant gas is sucked into thecompressive space, compressed therein and discharged therefrom.

In the sucking stroke of the piston, the coolant gas is sucked into theclosed container 10 through the suction pipe (SP), passes through a gasflow passage 31 a and the gas hole 31 b of the piston 31 and opens thesuction valve 33 so as to be sucked into the compressive space, and, ina compression stroke of the piston, the gas is compressed to apredetermined pressure and then discharged through the discharge pipe(DP) by opening the discharge valve assembly 34. The series of processesare repeatedly performed.

However, the conventional reciprocating compressor has a problem. Thatis, as the front spring 51 and the rear spring 52 are arranged in astraight line with the armature 22 therebetween, as shown in FIG. 2, thehorizontal directional length (L) of the spring should be equivalent toat least the sum of the length (L1) of the front spring 51 and thelength (L2) of the rear spring, causing a problem that the horizontallength of the compressor is lengthened.

In addition, the front spring 51 and the rear spring 52 are bothcompressive coil springs, which has a property of being deflected in theradial direction while being staggered in the winding direction when itis compressedly tensed. Thus, when the armature 22 and the piston 31 aremaking a reciprocal movement, they are vibrated in the radial directiondue to the characteristics of front spring 51 and the rear spring 52supporting them, resulting in that a general reliability of thecompressor is degraded.

DISCLOSURE OF THE INVENTION

Therefore, an object of the present invention is to provide a springsupport structure of a reciprocating compressor that is capable ofreducing a horizontal length of a compressor.

Another object of the present invention is to provide a spring supportstructure of a reciprocating compressor that is capable of reducing avibration in the radial direction due to a coil spring elasticallysupporting an armature and a piston of a compressor and improving astability of the compressor.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described herein,there is provided a spring support structure of a reciprocatingcompressor having a frame unit elastically supported inside a closedcontainer; a reciprocating motor fixed at the frame unit; a compressionunit having a piston combined to an armature of the reciprocating motorand a cylinder into which the piston is slidably-inserted to be fixed atthe frame unit; and a spring unit supporting a spring support providedat the armature or the piston and guiding a reciprocal movement of thepiston, wherein the spring unit includes a plurality of front springssupporting one side of the spring support in parallel and a plurality ofthe rear springs supporting the other side of the spring support.

The foregoing and other objects, features, aspects and advantages of thepresent invention will become more apparent from the following detaileddescription of the present invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention.

In the drawings:

FIG. 1 is a vertical-sectional view of a reciprocating compressor inaccordance with a conventional art;

FIG. 2 is a schematic view showing the total length of a spring of thereciprocating compressor in accordance with the conventional art;

FIG. 3 is a vertical-sectional view showing an example of areciprocating compressor in accordance with a preferred embodiment ofthe present invention;

FIG. 4 is a vertical-sectional view showing a state of supporting by aspring in the reciprocating compressor in accordance with the preferredembodiment of the present invention;

FIG. 5 is a perspective view showing an example of spring supports ofthe reciprocating compressor in accordance with the preferred embodimentof the present invention;

FIG. 6 is a sectional view taken along line ‘I—I’ of FIG. 5 inaccordance with the preferred embodiment of the present invention;

FIG. 7 is a modification of the spring support of the reciprocatingcompressor in accordance with the preferred embodiment of the presentinvention;

FIG. 8 is a sectional view taken along line ‘II—II’ of FIG. 7 inaccordance with the preferred embodiment of the present invention;

FIG. 9 is a schematic view showing the total length of a spring of thereciprocating compressor in accordance with the preferred embodiment ofthe present invention;

FIG. 10 is a plan view showing a mutual combination of the springsupport and the spring of the reciprocating compressor in accordancewith the preferred embodiment of the present invention; and

FIG. 11 is a sectional view taken along line ‘III—III’ of FIG. 10 inaccordance with the preferred embodiment of the present invention.

MODE FOR CARRYING OUT THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings.

FIG. 3 is a vertical-sectional view showing an example of areciprocating compressor in accordance with a preferred embodiment ofthe present invention, and FIG. 4 is a vertical-sectional view showing astate of supporting by a spring in the reciprocating compressor inaccordance with the preferred embodiment of the present invention.

As shown in FIGS. 3 and 4 a spring support structure of a reciprocatingcompressor of the present invention includes a spring support 100 fixedat a combining portion (not shown) between an armature 22 of areciprocating motor 20 and a piston 31 combined to the armature 22 so asto make a reciprocal movement together with the armature 22, frontsprings 51 and rear springs 52 respectively supported at both sides ofthe spring support 100 and guiding a reciprocal movement of the armature22 and the piston 31.

The spring support 100 includes a support body 110 fixed to the combingportion, front supports 120 integrally formed with the support body 110to support the front springs 51 in parallel and rear supports 130integrally formed with the support body together with the front supports120 and supporting the rear springs 52 in parallel.

FIG. 5 is a perspective view showing an example of spring supports ofthe reciprocating compressor in accordance with the preferred embodimentof the present invention.

As shown in FIG. 5, the front supports 120 and the rear supports 130 areopened in both directions on the basis of a vertical central line of theplane in which support body 110 lies, of which support combined with oneside of the front springs 51 becomes the front supports 120 and supportscombined with one side of the rear springs 52 becomes the rear supports130.

A plurality of the front supports 120 and the rear supports 130 (fourones) are formed at equal intervals, facing each other on the basis ofthe central axis of the support body 110.

FIG. 6 is a sectional view taken along line ‘I—I’ of FIG. 5 inaccordance with the preferred embodiment of the present invention.

As shown in FIG. 6, when viewed from each side, the front supports 120and the rear supports 130 includes slope face portions 121 and 131 bentat about 45° on the basis of a vertical central line of the plane inwhich the support body 110 lies and vertical portions 122 and 132 bentagain at the slope face portions 121 and 131. In this case, however,supports 120 and 130 may be formed to have a horizontal portion (notshown) and a vertical portion (not shown) without such a slope faceportion.

FIG. 7 is a modification of the spring support of the reciprocatingcompressor in accordance with the preferred embodiment of the presentinvention, and FIG. 8 is a sectional view taken along line ‘II—II’ ofFIG. 7 in accordance with the preferred embodiment of the presentinvention.

As shown in FIGS. 7 and 8, rear supports 230 are arranged in the samevertical line as that of the support body 210, while front supports 220may be formed including a vertical portion 221 bent perpendicularly inthe backward direction and a horizontal portion 222 bent againperpendicularly from the vertical portion 221.

Or, conversely, the front supports 220 may be arranged in the samevertical line as that of the support body 210, while the rear supports230 may be formed bent perpendicularly.

The both cases are proposed in consideration of an installation space ofthe springs 51 and 52. Thus, if a space for installing the springs 51and 52 are sufficient, one of the supports 220 and 230 can be bentslope.

It is preferred to form fixing protrusions 120 a, 220 a, 130 a and 230 aat each support face of the front supports 120 and 220 and the rearsupports 130 and 230, to press-fit and fix one ends of the front springs51 and the rear springs 52.

The front springs 51 and the rear springs 52 are all compressive coilsprings. The other ends of the front springs 51 are tightly supported bythe front frame 51 or the middle frame 42 of the frame unit 40 where thereciprocating motor 20 is fixed, and the other ends of the rear springs52 are tightly supported by the inner face of the rear frame 43 combinedwith the rear side of the reciprocating motor 20.

FIG. 9 is a schematic view showing the total length of a spring of thereciprocating compressor in accordance with the preferred embodiment ofthe present invention.

As shown in FIG. 9, one end of the front springs 51 fixed to the frontsupports 120 and 220 and one end of the rear springs 52 fixed at therear supports 130 and 230 are arranged to overlap with each other withina predetermined range as the front supports 120 and 220 and the rearsupports 130 and 230 are bent toward the opposite side to each other.

FIG. 10 is a plain view showing a mutual combination of the springsupport and the spring of the reciprocating compressor in accordancewith the preferred embodiment of the present invention, and FIG. 11 is asectional view taken along line ‘III—III’ of FIG. 10 in accordance withthe preferred embodiment of the present invention.

As shown in FIGS. 10 and 11, it is preferred that the ends (a) of eachspring line of springs 51 and 52 are arranged symmetrical to be directedto the central axis of the support body 110.

The same elements as those of the conventional art are given the samereference numerals.

A reference numeral 10 denotes a closed container, 21A and 21B denote aninner stator and an outer stator, 30 denotes a compression unit, 32denotes a cylinder, 33 denotes a suction valve, 34 denotes a dischargevalve assembly, SP denotes a suction pipe, and DP denotes a dischargepipe.

The general operation of the reciprocating compressor of the presentinvention is the same as that of the conventional art.

That is, when a power is applied to the reciprocating motor 20 and aflux is formed at the stator 21, the armature 22 is moved in thedirection of the flux along with the piston 31 to make a reciprocalmovement linearly by virtue of the spring unit 50. At this time, as thepiston 31 makes a reciprocal movement inside the cylinder 32, a pressuredifference is made in the compressive space of the cylinder 32. Owing tothe pressure difference, a coolant gas is sucked into the compressivespace of the cylinder 32 through the gas flow passage 31 a of the piston31, compressed and discharged. The series of processes are performedrepeatedly.

At this time, the front springs 51 and the rear springs 52 arealternately arranged and the rear end of the front spring 51 is arrangedto overlap with the front end of the rear spring 52, so that the length(L′) from the front end of the front spring 51 to the rear end of therear spring 52 is shorter than the length according to the sum of thelength (L1) of the front spring 51 and the length (L2) of the rearspring 52. Thus, the horizontal length of the compressor is reduced to acompact size.

In addition, the front springs 51 and the rear springs 52 are arrangedat equal intervals and the ends (a) of the spring lines of the springs51 and 52 are arranged symmetrical to be directed to the central axis ofthe support body 110, so that when springs 51 and 52 are compressedlytensed, tendencies that the springs are deflected to a side and vibratedin the radial direction are offset each other, and thus, the armature 22and the piston 31 can be stably moved reciprocally. Moreover, sinceabrasion made between the springs 51 and 52, the spring support 100 andthe frame unit 40 as the springs 51 and 52 are rotated can berestrained, the reliability of the compressor can be improved.

As so far described, the spring support structure of the reciprocatingcompressor has many advantages.

That is, for example, since the front springs and the rear springselasitcally supporting both the armature and the piston are arranged inparallel to overlap with each other for a certain range, the horizontallength of the spring is reduced, resulting in that the compressor can becompact.

In addition, since the several spring lines are arranged symmetrical,the deflection occurring due to the characteristics of the coil springis offset to reduce the vibration of the compressor in the radialdirection as well as to prevent the spring support which is relativelyhard from abrading. As a result, the reliability of the compressor canbe improved.

As the present invention may be embodied in several forms withoutdeparting from the spirit or essential characteristics thereof, itshould also be understood that the above-described embodiments are notlimited by any of the details of the foregoing description, unlessotherwise specified, but rather should be construed broadly within itsspirit and scope as defined in the appended claims, and therefore allchanges and modifications that fall within the meets and bounds of theclaims, or equivalence of such meets and bounds are therefore intendedto be embraced by the appended claims.

What is claimed is:
 1. A spring support structure of a reciprocatingcompressor having a frame unit elastically supported inside a closedcontainer; a reciprocating motor fixed at the frame unit; a compressionunit having a piston combined to an armature of the reciprocating motorand a cylinder into which the piston is slidably inserted to be fixed atthe frame unit; and a spring unit supporting a spring support providedat the armature or the piston and guiding a reciprocal movement of thepiston, wherein the spring unit includes a plurality of front springssupporting one side of the spring support in parallel and a plurality ofthe rear springs supporting the other side of the spring support, aplurality of front supports integrally formed with a support body tosupport the front spring, and a plurality of rear supports independentfrom the front support and integrally formed with the support body tosupport the rear spring.
 2. The structure of claim 1, wherein the frontsprings and the rear springs are arranged symmetrical to each other withreference to a central axis of the spring support.
 3. The structure ofclaim 1, wherein each spring line of the front springs and the rearsprings comprise ends that are arranged symmetrical to each other withrespect to a central axis of the spring support.
 4. The structure ofclaim 3, wherein ends of the front springs and the rear springs arearranged to be directed toward the central axis.
 5. The structure ofclaim 1, wherein the spring support comprises: a support body fixed atthe armature or the piston.
 6. The structure of claim 5, wherein thefront support is located within the length of the rear spring on thebasis of a vertical central line of the plane in which the the length ofthe front spring on the basis of the vertical central line.
 7. Thestructure of claim 5, wherein the front support and the rear support areformed symmetrically with respect to a vertical central line of theplane in which the support body lies.
 8. The structure of claim 5,wherein one of the front support and the rear support is located in thesame vertical central line of the plane in which the support body lies,and the other is formed bent to have a certain interval from thevertical central line of the plane in which the support body lies. 9.The structure of claim 8, wherein when one of the front support and therear support is formed bent, it is bent perpendicularly to the plane inwhich the support body lies.
 10. The structure of claim 1, wherein thefront support and the rear support are formed bent to have a certainslope face on the basis of the vertical central line of the plane inwhich the support body lies.
 11. The structure of claim 1, wherein thefront spring and the rear spring are arranged to have a range in whichthey overlap with each other.
 12. A spring support structure of areciprocating compressor having a frame unit elastically supportedinside a closed container; a reciprocating motor fixed at the frameunit; a compression unit having a piston combined to an armature of thereciprocating motor and a cylinder into which the piston is slidablyinserted to be, fixed at the frame unit; and a spring unit supporting aspring support provided at the armature or the piston and guiding areciprocal movement of the piston, wherein the spring unit includes aplurality of front springs supporting one side of the spring support inparallel and a plurality of the rear springs supporting the other sideof the spring support, and wherein the spring support comprises asupport body fixed at the armature or the piston, a front supportintegrally formed with the support body to support the front spring, anda rear support integrally formed with the support body to support therear spring, and wherein, the front support and the rear support areformed symmetrically with respect to a vertical central line of theplane in which the support body lies, and wherein the front support andthe rear support are formed bent to have a certain slope face on thebasis of the vertical central line of the plane in which the supportbody lies.